Again, everything you say is is true (which, BTW, is why I prefaced my comment with "Just FYI..."). But the sarcasm/ironic-humor confusion is very prevalent even among native speakers, and in a different set of circumstances it could cause confusion or worse because the implied stance of sarcasm is the exact opposite of ironic humor. Also, HN is a public forum, and comments are read not only by their respondees but by lurkers as well, some of whom may not be native speakers and who might therefore appreciate having some of the subtleties of the language pointed out to them.

After reading all the comments here, you still stand behind your original pedantic comment as being appropriate and productive? Fascinating.

If you knew the OP was more likely to feel insulted than to feel helped, that wouldn't have changed your action?

Well, we don't have to speculate. The OP weighed in:

> Just to be clear, I quite liked Lister's [sic] note as well.

So yes.